1. Field of Invention
This welding helmet invention improves welder comfort using a thermoelectric device and a quality filter to deliver clean, cool air to a welders head and neck. It utilizes an innovative design to more than double the energy efficiency required to achieve the very positive result.
2. Background
Welding is considered a hot and dirty occupation by many professional welders. Recently, allowable maximum levels of fume constituents from arc welding are at such low levels that conventional means of staying below these levels are not sufficient. For example, the current maximum recommended fume exposure level for some chrome (VI) compounds is 0.01 mg/m3. Even employing source capture may not be sufficient to assure welder exposure levels are below that maximum safe level. When welding steel, some fume constituents may also exceed newly reduced maximum fume constituent levels. This may require a welder to use a high quality respirator under their normal welding helmet making the hot working environment even more objectionable. Welding often occurs in shops which are not cooled in warm weather and the use of devices such as respirators makes the welding occupation less attractive. When welding in very toxic environments air has been delivered to welding helmets from an external source through a long hose. This is not practical or desirable for most welding applications.
3. Description of Prior Art
There have been welding helmet designs that attempt to address some of the environmental problems encountered while welding:    (a) Walters in U.S. Pat. No. 3,548,415 (1968) entitled “Air Conditioned Helmet,” describes a device that incorporates a fan enclosed in an open helmet, not one used for welding. It discusses several means of creating cooling such as gels, heat pipes and mentions but does not elaborate on the possible use of a thermoelectric principle. As with many of the devices reviewed, this one relies on battery power. It also does not mention any means of reducing welding fume levels to a very low level nor would the design with its open helmet arrangement accomplish this task.    (b) Greenlee in U.S. Pat. No. 3,535,707 (1970) entitled “Welding Helmet and the Like,” describes a welding helmet with a fan in the front which draws air from the rear of the helmet. The back of this helmet, as with most welding helmets, is open. At the very low allowable concentrations of some welding fume constituents this approach would not provide sufficiently low fume breathing air in many welding applications.    (c) Martin, et al in a US patent application 2007/0056073 entitled “Modular Auto-Darkening Welding Filter,” discusses a feature that would be used in this invention, an adjustable shade auto-darkening welding lens using external knobs to adjust some of the functions of the helmet. External adjustment of auto-darkening welding lens shade is common to some commercial welding helmets.    (d) Apisdorf in U.S. Pat. No. 5,193,317 (1993) and reissue Pat. RE 36,242 (1999) entitled “Helmet-Mounted Air System for Personal Comfort,” describes the use of a helmet that incorporates a thermoelectric device to cool the air brought in by a fan. The helmet is open such that the cool air exits the helmet after passing the welders face one time and the cool air does not assist cooling the thermoelectric hot side heat sink. The patent claims the use of a battery that is body mountable to power the device. They discuss the small amount of cooling the device provides and justify the low amount as being sufficient to cause comfort. They emphasize the cool air is brought to the face and the design shows it exits the helmet area after it enters. They appear to justify low levels of flow and a small amount of cooling to support a key claim for the device of being capable of using a body mountable battery.    (e) Buckman in U.S. Pat. No. 7,534,005 (2009) entitled “Welding Helmet,” and prior U.S. Pat. No. 7,178,932 describes the use of multiple fans and a filter. One figure also shows a type of helmet skirt. However, the claims describe a conventional welding helmet with only front and sides, not the back or the top of the welders head covered. There is also no mention of a cooling device of the thermoelectric type or of any type that would significantly improve the welder's temperature environment.    (f) Johnson in U.S. Pat. No. 5,896,579 describes a welding helmet with a fan and a device for employing evaporation cooling. As with most of the prior art discovered the helmet described also has a typical open back and would not provide the sufficiently clean breathing air needed in many welding environments.    (g) Goldsborough in U.S. Pat. No. 7,296,304 describes a race car crash helmet that contains Peltier thermoelectric modules located around the periphery of the helmet shell. However the cooled air exits the helmet at the bottom and other openings and is not sealed. This patent does discuss providing power from a cigarette lighter receptacle which is readily available in a conventional automobile. However there is no attempt to filter the air or improve efficiency by using the cooled air exhausted from the helmet to assist in cooling the thermoelectric hot side heat sinks.